Mitt Romney swept three Republican presidential primaries, putting him one step closer to the party's nomination. Romney led by late Tuesday in the important north-central state of Wisconsin with 42 per cent of the votes over chief rival Rick Santorum's 38 per cent with more than 70 per cent of the votes counted, according to a report of DPA. In the eastern state of Maryland, Romney led with 48 per cent to Santorum's 30 per cent with 60 per cent of the votes counted. And in the District of Columbia, the nation's capital, Romney led with 70 per cent of the vote in a contest that Santorum never entered. The two other remaining Republican candidates, Newt Gingrich and Ron Paul, lagged far behind in third and fourth place in Tuesday's three races.
